Dental device and method of denttyse constbuction



F. M. WADSWORTH.

DENTAL DEVICE AND METHOD OF DENTURE CONSTRUCTIONI.

APPLICATION men FEB. [5.19I8.

1,3 1 9,737. Patented 001:. 2a, 1919.

(mmmamrmumamuuuu V In men fo r Frank M. Wadsworfh FRANK M. WADSWOBTH, OF MINNEAPOLIS, MINNESOTA.

DENTAL DEVICE AND METHOD OF DENTUB-E CONSTRUCTION.

Specification of Letters Patent.

Patented Oct. 28, 1919.

Application filed February 15, 1918. Serial No. 217,464.

To all whom it may concern I Be it known that I, FRANK M. WADS- wonm, a citizen of the United States, and a resident ofMinneapolis, in the county of Hennepin and State of Minnesota; have invented certain new and useful Improvements in Dental Devices and Methods of Denture Construction, of which the following is a specification. t

The main object of my invention is to provide in a dental device, means for establishing the cusp planes in partial dentures.

I Another object of in invention is to provide means for re roducing the action of the temporal man ihular articulation.

Another object of my invention is to provide adjustment means for the parts of the device re resenting the temporal mandibular articu ation.

With those and incidental objects in view the invention consists of certain novel features of construction and combination of parts, the essential elements of which are hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

In the drawing Fi ure 1 is an isometric view of my improve dental device, carrying thereon the reproduction of a set of teeth; Fig. 2 is a section taken on the line 22, Fig. 1, and Fig. 3 is a section of one of the teeth to illustrate the position of the cusp plane.

In Fig. the tooth 1 is shown in full lines, as it uould normally be set in a human jaw,

and the l ne 33 repres nts what 1 term the cusp planes; that is, the plane representing the surface of one of the cusps. Fig. 4 is a section taken on the line l -l,

hrough the natural wear of tooth during life, the cusp planes become distorted, and particularly, when a tooth is extracted the adjacent tooth will tend to move from its original position, as. for instance, to the position shown dotted in Fig. 3, when the cusp plane will then be along the line 44 instead of the line 33.

When replacing the extracted tooth by a porcelain tooth, in any manner, the cusp plane of the porcelain tooth should be round to coincide with the cus plane of t e opposing 00th, or the adjacent teeth as the proper joining of the cusp planes of the opposing tact determine the cutting and grindingcapacityof the individual tooth.

In replacing the extracted teeth I therefore reproduce the teeth in the casts 5 and 6 in the ordinary manner, the tooth 7 in this case being the one to be replaced and the tooth 8 being the opposing tooth whose cusp plane is to be established in order to reproduce a co-acting plane in the porcc lain tooth at 7.

A frame 8, having two uprights 9 and 10,

carries a T-shaped bar 11 having slidablc trunnious 12 resting on the uprights 9 and 10.

A spring 12, connecting the trunnion with the frame, restrain; its vertical movement, a similar spring, not shown, restraining the vertical movement of theopposite trunnion.

Adjustment screws 13 provide means for adjusting the trunnions 12 on the angle of the members 14.

This sliding action along the members 1-1 reproduces the action of the temporal mandibular articulation of a human being, so that by adjusting the screws 13 it is pos sible to reproduce all positions of the teeth in the casts 5 and 6 that could be produced by the action of the jaws.

It is to be noted here that in the human jaw and in my device a sidewisc movement of the jaw is produced, not by swinging it about the centrally located point, such as 15. but by movement of one or both of the joints formed of glenoid fossac of the temporal bone and the condyloid process of the maudilmlur. hence an adjustment to reproduce the action of the human jaw ,must providc adjustments on the two sides individually and not an adjustment around a central point such as 15.

The frame member 8 carries a forward forked extension 16 on which is slidably mountcd a table 17 whose longitudinal position on the forked extension may be adjusted by loosening the thumb screw 18.

Hinged in the table 17 are two individual leaves 19 and 20, the thumb screw 21 being provided to tighten the hinged action of the leaves.

A thumb screw 22 and a similar thumb The T-shaped member 11 carries in i" marked in d forward forked end a gage oint 23 northe rizontal hinged joint of the leaves 19 and 20.

7 Thumb nuts and screws '24 and 25 provide means for adjusting the gage point 23- lVith the thumb screw 22 retracted and the porcelain tooth fitted against the opposin tooth 8, the action of the temporal mandigular articulation is reproduced b swinging one of the trunnions 12 upward y along its incline 14, "the gage point 23 riding along one of the leaves and swinging that leaf into a plane corresponding to that of the cusp plane of the opposing tooth 8 or the ad'acent teeth.

f the cusp plane of the porcelain tooth does not properly fit the cusp plane of the o posing tooth, it is then ground away 5 ightly and replaced in the cast, and the test repeated until the cusp plane of the porcelain tooth has been ground to fit the cusp plane of the opposing tooth and the adjacent teeth during the reproducing action of the temporal mandibular articulation.

The action is similarly tested on the opsite cusp lane b adjusting the posite eaf, and t e qua rant 26 is pre erably to facilitate the grinding of the pores ain tooth to bring its cusp planes to the proper angles.

Looking at the leaves 19 and 20, it will be seen that the central portion of each leaf has its upper surface lying in planes 27 and 28, while on one end the surfaces 29 and 30 are convex, whereas on the other end the surfaces 31 and 32 are concave. This construction provides means for following with the pointer 23 either a plane surface, a con vex surface, or a concave surface, depending upon whether the pointer 23 is posi tioned so as to rest on the plane, convex, or concave surface.

While I am aware that dental devices have been made for the purpose of fitting teeth, I believe myself to be the first to pro duce any means for establishing the cusp plane of a. tooth for the purpose of fittinga porcelain tooth in a partial denture, and shall clairmthis point broadly, together with incidental adjustin devices.

Therefore, while have described my invention and illustrated it in one particular design, I do not wish it understood that I limit myself to this construction, as it is malli positioned in the vertical plane ofthereon.

3. In a dental device thcficombination of means for carrying in movable relation a. reproduction of a set of teeth, an adjustable leaf associated therewith, a part of said leaf havin a convex surface.

4. n a dental device the combination of means for carrying in movable relation a reproduction of a set of teeth, two adjustable leaves associated therewith, a part of one of said leaves having a concave surface, one part havin a convex surface, and one part avin a p ane surface.

5. 1% a dental device the combination of means for determining the angles of the,

cusp planes of the natural teeth, indicating means on said device positioned erpendicularly to said first named means or registering said angles, and locking means on said device for locking said registering means so it may be used in grinding cusp planes of artificial teeth to correspond with those of the natural teeth.

6. In a dental device a loaf support for a gage point rotatable vertically in the device,

.said leaf having its axis of rotation in the same plane as its upper surface.

7. In a dental device a leaf support for a gage point rotatable vertically in the device. said leaf having its axis of rotation in the same lane as its upper surface, and a aduated scale to show the angle of sai leaf. positioned per endicular to the axis of rotation of said eaf support.

8. In a dental device a leaf support for a gage point rotatable vertically in'tlie device, said leaf having its axis of rotation in the same plane as its upper surface, and a locking device to positively position said leaf.

FRANK M. WADSWORTH. 

